SALVE - Cs/Cc corrector for TEM (low-kV range)
The abbreviation SALVE stands for Sub-Angstrom-Low-Voltage-Electron microscope (www.salve-project.de), which is a research project of the University of Ulm, the company ThermoFisherScientific and the company CEOS. Therein, a special Cc/Cs-corrector was developed by CEOS for special use in low-voltage transmission electron microscopy in the range from 20 kV to 80 kV. The limitation to low accelerating voltages is extremely important to avoid damage in electron beam sensitive objects. The SALVE Cc/Cs-corrector is a quadrupol-octupole-corrector, which eliminates not only the 3rd order spherical aberration Cs=C3 but also the off-axial coma B3, and moreover corrects for the linear chromatic aberration Cc. The correction of Cc requires not only magnetic multipole fields but also very strong electrostatic quadrupole elements (up to +/- 8kV). CEOS is the only company world-wide, which successfully applies this elaborate technology for aberration correction in TEM. The optical design additionally allows for a complete correction of all axial aberration up to including 5th order as well as all off-axial aberrations up to including 3rd order. The intrinsic (+) spherical aberration of 5th order (C5) of the SALVE corrector was carefully optimized for ideal phase contrast imaging conditions for a large aperture angle of at least 50 mrad. This enables high-contrast imaging of light atoms (weak phase objects) over the whole high voltage range.The correction of the chromatic aberration Cc does not only considerably improve the TEM's information limit (resoving power), but also enables a much higher image contrast due to the additional contrast contribution of inelastically scattered electrons which only form a blurred image background in Cc-uncorrected images.For these reasons, the SALVE Cc/Cs-corrector is the ideal equipment for high-resolution TEM investigations on electron beam sensitive objects like graphene or bio-molecules, as well as for spectroscopic imaging (EFTEM).
You can find more information about the SALVE corrector in our publication:
M. Linck, P. Hartel, S.Uhlemann, F. Frank, H. Müller, J. Zach, M. Haider. Chromatic Aberration Correction for Atomic Resolution TEM Imaging from 20 to 80 kV. Physical Review Letters, 117, 076101 (2016).
and on www.salve-project.de
(+) intrinsic aberrations = aberrations that occur and are unavoidable due to the optical design of the corrector.
- Quadrupole-octupole type corrector for low-voltage TEM
- Simultanious correction of the chromatic aberration Cc, the spherical aberration Cs=C3 and the off-axial coma B3
- Ajustable for the high-voltage range from 20 kV up to 80 kV.
- Correction of all axial aberrations up to 5th order (A1, B2, A2, C3, S3, A3, B4, D4, A4, C5, S5, R5, A5).
- Corrects off-axial aberrations up to including 3rd order(A1g/G, A2g/G, B2g/G)
- Optimized sphercial aberration of fifth order (C5) for ideal phase contast imaging conditions for an optical aperure of at least 50mrad over the whole high-tension range
- Compared to the use of a monochromator for resolution improvment Cc correction offers a much more intense electron beam at the same or better image resolution and therefore allows much shorter exposure times hence higher throughput.
- Higher image contrast due to additional high-resolution contrast contribution from inelastically scattered electrons by Cc correction.
- Less knock-on damage on electron beam sensitive samples and, at the same time, highest resolution imaging, due to the combination of low acceleration voltage with Cc/Cs-correction.
- Compatible with the following TEMs: TFS (TitanTM Themis)
- Device dimensions: 468 x 560 x 560 [mm]
- Mode: TEM
- High voltage range: 20kV – 80kV
- Target resolution: Proper phase contrast imaging conditions to at least 50 mrad aperture angle. Experimental reolution at different high-tensions:
- 62 mrad (Aperture angle) - 20 kV (High voltage) - 139 pm (Information limit)
- 61 mrad (Aperture angle) - 30 kV (High voltage) - 115 pm (Information limit)
- 67 mrad (Aperture angle) - 40 kV (High voltage) - 90 pm (Information limit)
- 59 mrad (Aperture angle) - 60 kV (High voltage) - 83 pm (Information limit)
- 55 mrad (Aperture angle) - 80 kV (High voltage) - 76 pm (Information limit)
- High-resolution TEM for electron beam sensitive samples at low accelerating voltages (20kV – 80kV), e.g. thin and light materials such as graphene, lithium compounds or bio-molecules
- Spectroscopic imaging (EFTEM)
Do you have any questions about the product or the application and extension for your e-beam system? Please contact us at firstname.lastname@example.org